Hanna Farnelid

Associate professor

Department of Biology and Environmental Science Faculty of Health and Life Sciences

hanna.farnelid@lnu.se

+46 480-44 62 96

+46 72-594 98 20

I’m an associate professor in marine ecology. I have a PhD in microbiology and an engineering degree from Chalmers University of Technology in Biotechnology. I study phytoplankton and bacteria with a focus on microbial diversity, distribution and functionality. In my research I use traditional microbial methods in combination with in situ studies and molecular methods. I am particularly interested in genetic microdiversity within microbial lineages and their consequences for ecosystem functioning.

Teaching

I teach in a number of microbiology and marine ecology courses within the BSc program in biology and the MSc program in aquatic ecology. I supervise first, second, and third level thesis students.

Research

My research interests are within aquatic microbial ecology with a focus on microbial diversity and functionality. I study phytoplankton and bacteria interactions with a focus on processes such as carbon and nitrogen fixation. My current research is focusing on microdiversity and econiches of Synechococcus sublineages.

Commissions

Swedish Institute for the Marine Environment (Environmental analyst 10%)

My research groups

My ongoing research projects

My completed research projects

Project: Consequences of climate change in a Baltic Sea bay exposed to 50 years of warming Today, there is little knowledge of the consequences of global warming on Baltic Sea ecosystems and aquatic…

Publications

Article in journal (Refereed)

Key, R.S., Coesel, S.N., Gradoville, M.R., Morales, R.L., Farnelid, H., et al. (2026). Picophytoplankton implicated in productivity and biogeochemistry in the North Pacific Transition Zone. mSystems. 11 (2).
Status: Published
Furbo reeder, C., Winberg von friesen, L., Lemke, J., Spilling, K., Farnelid, H. (2026). Composition of non-cyanobacterial diazotrophs in suspended and sinking particles is driven by productivity phase. Microbiology Spectrum. 14 (9).
Status: Published
Nham, T.Q., Farnelid, H., Legrand, C., Lindehoff, E. (2026). Species Dynamics and Gene Expression in Algal Polycultures Under Mixotrophic Cultivation in Outdoor Pilot-Scale Nordic Conditions. Biotechnology and Bioengineering.
Status: Epub ahead of print
Mollica, T., Farnelid, H., Lindehoff, E., Lundin, D., Pinhassi, J., et al. (2026). Phosphorus Acquisition Strategies Among Phytoplankton and Free-Living Bacterial Communities in the Baltic Proper. Environmental Microbiology Reports. 18 (2).
Status: Published
Churakova, Y., Lundin, D., Charalampous, E., Aguilera, A., Pontiller, B., et al. (2026). Metatranscriptomics analysis of silicon transporters highlights underappreciated contributors to silica cycling in the Baltic Sea. Limnology and Oceanography Letters. 11 (5).
Status: Published
Fernandez-roman, D., Fontela, M., Broullon, E., Farnelid, H., Fernandez-carrera, A., et al. (2026). Transient Ecological Niches for Diazotrophs in Upwelling Bays. Journal of Geophysical Research - Oceans. 131 (8).
Status: Published
Nham, T.Q., Gordon, T., Farnelid, H., Legrand, C., Lindehoff, E. (2025). Mitigating Night Biomass Loss in Outdoor Pilot-Scale Mixotrophic Algal Cultivation of Monoraphidium minutum Using Flue Gas Condensate and Cheese Whey. Biotechnology and Bioengineering. 122. 2688-2700.
Status: Published
Winberg von friesen, L., Farnelid, H., Von appen, W., Benavides, M., Grosso, O., et al. (2025). Nitrogen fixation under declining Arctic sea ice. Communications Earth & Environment. 6 (1).
Status: Published
Fontela, M., Fernandez-roman, D., Broullon, E., Farnelid, H., Fernandez-carrera, A., et al. (2025). Puzzling out the ecological niche construction for nitrogen fixers in a coastal upwelling system. ISME Communications. 5 (1).
Status: Published
Churakova, Y., Aguilera, A., Charalampous, E., Conley, D.J., Lundin, D., et al. (2025). Seasonal dynamics and nutrient controls of biogenic silica in Baltic Sea surface microplankton and picoplankton communities. Applied and Environmental Microbiology. 91 (5).
Status: Published
Aguilera, A., Lundin, D., Charalampous, E., Churakova, Y., Tellgren-roth, C., et al. (2025). The evaluation of biogenic silica in brackish and freshwater strains reveals links between phylogeny and silica accumulation in picocyanobacteria. Applied and Environmental Microbiology. 91 (4).
Status: Published
Winberg von friesen, L., Laber, C.P., Kristensen, B.H., Nysted, E., Sundbom, M., et al. (2025). From temperate to polar waters : Transition to non-cyanobacterial diazotrophy upon entering the Atlantic gateway of the Arctic Ocean. Limnology and Oceanography. 70 (10). 2793-3102.
Status: Published
Winberg von friesen, L., Loscher, C.R., Bertilsson, S., Farnelid, H., Snoeijs-leijonmalm, P., et al. (2025). Nitrogen Fixation Potential in Bathypelagic Sediment of the Ice-Covered Arctic Ocean Revealed Through Long-Term Stable Isotope Incubations. Environmental Microbiology Reports. 17 (5).
Status: Published
Mollica, T., Farnelid, H., Lindehoff, E., Legrand, C. (2025). Smaller phytoplankton size-groups control the stoichiometry of the autotrophic community. Limnology and Oceanography. 70 (7). 1947-1961.
Status: Published
Vermassen, F., Bird, C., Weitkamp, T.M., Darling, K.F., Farnelid, H., et al. (2025). The distribution and abundance of planktonic foraminifera under summer sea ice in the Arctic Ocean. Biogeosciences. 22 (9). 2261-2286.
Status: Published
Lindehoff, E., Mattsson, L., Olofsson, M., Svensson, F., Farnelid, H., et al. (2024). Biomass performance and stability of 5-year outdoor microalgal cultivation for CO₂ removal from cement flue gas. Bioresource Technology Reports. 25.
Status: Published
Alegria zufia, J., Laber, C.P., Legrand, C., Lindehoff, E., Farnelid, H. (2024). Growth and mortality rates of picophytoplankton in the Baltic Sea Proper. Marine Ecology Progress Series. 735. 63-76.
Status: Published
Dutkiewicz, S., Follett, C.L., Follows, M.J., Henderikx-freitas, F., Ribalet, F., et al. (2024). Multiple biotic interactions establish phytoplankton community structure across environmental gradients. Limnology and Oceanography. 69 (5). 1086-1100.
Status: Published
Mattsson, L., Farnelid, H., Hirwa, M., Olofsson, M., Svensson, F., et al. (2024). Seasonal nitrogen removal in an outdoor microalgal polyculture at Nordic conditions. Water environment research. 96 (10).
Status: Published
Laber, C.P., Alegria zufia, J., Legrand, C., Lindehoff, E., Farnelid, H. (2024). Colony-forming and single-cell picocyanobacteria nitrogen acquisition strategies and carbon fixation in the brackish Baltic Sea. Limnology and Oceanography. 69 (9). 1955-1969.
Status: Published
Weissenbach, J., Aguilera, A., Bas conn, L., Pinhassi, J., Legrand, C., et al. (2024). Ploidy levels in diverse picocyanobacteria from the Baltic Sea. Environmental Microbiology Reports. 16 (5).
Status: Published
Hylander, S., Farnelid, H., Fridolfsson, E., Hauber, M.M., Todisco, V., et al. (2024). Thiamin (vitamin B1, thiamine) transfer in the aquatic food web from lower to higher trophic levels. PLOS ONE. 19 (12).
Status: Published
Fridolfsson, E., Bunse, C., Lindehoff, E., Farnelid, H., Pontiller, B., et al. (2023). Multiyear analysis uncovers coordinated seasonality in stocks and composition of the planktonic food web in the Baltic Sea proper. Scientific Reports. 13 (1).
Status: Published
Churakova, Y., Aguilera, A., Charalampous, E., Conley, D.J., Lundin, D., et al. (2023). Biogenic silica accumulation in picoeukaryotes : Novel players in the marine silica cycle. Environmental Microbiology Reports. 15 (4). 282-290.
Status: Published
Aguilera, A., Alegria zufia, J., Bas conn, L., Gurlit, L., Śliwińska‐wilczewska, S., et al. (2023). Ecophysiological analysis reveals distinct environmental preferences in closely related Baltic Sea picocyanobacteria. Environmental Microbiology. 25 (9). 1674-1695.
Status: Published
Pinhassi, J., Farnelid, H., Garcia, S.M., Teira, E., Galand, P.E., et al. (2022). Functional responses of key marine bacteria to environmental change - toward genetic counselling for coastal waters. Frontiers in Microbiology. 13.
Status: Published
Laber, C.P., Pontiller, B., Bunse, C., Osbeck, C.M.G., Pérez martínez, C., et al. (2022). Seasonal and Spatial Variations in Synechococcus Abundance and Diversity Throughout the Gullmar Fjord, Swedish Skagerrak. Frontiers in Microbiology. 13.
Status: Published
Alegria zufia, J., Legrand, C., Farnelid, H. (2022). Seasonal dynamics in picocyanobacterial abundance and clade composition at coastal and offshore stations in the Baltic Sea. Scientific Reports. 12 (1).
Status: Published
Farnelid, H., Turk-kubo, K., Zehr, J.P. (2021). Cell sorting reveals few novel prokaryote and photosynthetic picoeukaryote associations in the oligotrophic ocean. Environmental Microbiology. 23 (3). 1469-1480.
Status: Published
Alegria zufia, J., Farnelid, H., Legrand, C. (2021). Seasonality of Coastal Picophytoplankton Growth, Nutrient Limitation, and Biomass Contribution. Frontiers in Microbiology. 12.
Status: Published
Mattsson, L., Sörenson, E., Capo, E., Farnelid, H., Hirwa, M., et al. (2021). Functional Diversity Facilitates Stability Under Environmental Changes in an Outdoor Microalgal Cultivation System. Frontiers in Bioengineering and Biotechnology. 9.
Status: Published
Izabel-shen, D., Albert, S., Winder, M., Farnelid, H., Nascimento, F.J.A. (2021). Quality of phytoplankton deposition structures bacterial communities at the water-sediment interface. Molecular Ecology. 30 (14). 3515-3529.
Status: Published
Sörenson, E., Capo, E., Farnelid, H., Lindehoff, E., Legrand, C. (2021). Temperature Stress Induces Shift From Co-Existence to Competition for Organic Carbon in Microalgae-Bacterial Photobioreactor Community – Enabling Continuous Production of Microalgal Biomass. Frontiers in Microbiology. 12 (11 February). 1-17.
Status: Published
Gradoville, M.R., Farnelid, H., White, A.E., Turk-kubo, K.A., Stewart, B., et al. (2020). Latitudinal constraints on the abundance and activity of the cyanobacterium UCYN-A and other marine diazotrophs in the North Pacific. Limnology and Oceanography. 65 (8). 1858-1875.
Status: Published
Sörenson, E., Farnelid, H., Lindehoff, E., Legrand, C. (2020). Resource Partitioning Between Phytoplankton and Bacteria in the Coastal Baltic Sea. Frontiers in Marine Science. 7. 1-19.
Status: Published
Sörenson, E., Bertos-fortis, M., Farnelid, H., Kremp, A., Kruget, K., et al. (2019). Consistency in microbiomes in cultures of Alexandrium species isolated from brackish and marine waters. Environmental Microbiology Reports. 11 (3). 425-433.
Status: Published
Farnelid, H., Turk-kubo, K., Ploug, H., Ossolinski, J.E., Collins, J.R., et al. (2019). Diverse diazotrophs are present on sinking particles in the North Pacific Subtropical Gyre. The ISME Journal. 13 (1). 170-182.
Status: Published
Del carmen munoz-marin, M., Shilova, I.N., Shi, T., Farnelid, H., Maria cabello, A., et al. (2019). The Transcriptional Cycle Is Suited to Daytime N₂ Fixation in the Unicellular Cyanobacterium “Candidatus Atelocyanobacterium thalassa” (UCYN-A). mBio. 10 (1). 1-17.
Status: Published
Cornejo-castillo, F.M., Del carmen munoz-marin, M., Turk-kubo, K.A., Royo-llonch, M., Farnelid, H., et al. (2019). UCYN-A3, a newly characterized open ocean sublineage of the symbiotic N₂-fixing cyanobacterium Candidatus Atelocyanobacterium thalassa. Environmental Microbiology. 21 (1). 111-124.
Status: Published
Turk-kubo, K.A., Connell, P., Caron, D., Hogan, M.E., Farnelid, H., et al. (2018). In Situ Diazotroph Population Dynamics Under Different Resource Ratios in the North Pacific Subtropical Gyre. Frontiers in Microbiology. 9.
Status: Published
Zehr, J.P., Shilova, I.N., Farnelid, H., Muñoz-marín, M.D.C., Turk-kubo, K.A. (2017). Unusual marine unicellular symbiosis with the nitrogen-fixing cyanobacterium UCYN-A. Nature Microbiology. 2 (1). 1-10.
Status: Published
Turk-kubo, K.A., Farnelid, H., Shilova, I.N., Henke, B., Zehr, J.P. (2017). Distinct ecological niches of marine symbiotic N₂-fixing cyanobacterium Candidatus Atelocyanobacterium thalassa sublineages. Journal of Phycology. 53 (2). 451-461.
Status: Published
Farnelid, H., Turk-kubo, K.A., Zehr, J.P. (2016). Identification of Associations between Bacterioplankton and Photosynthetic Picoeukaryotes in Coastal Waters. Frontiers in Microbiology. 7.
Status: Published
Bertos-fortis, M., Farnelid, H., Lindh, M.V., Casini, M., Andersson, A., et al. (2016). Unscrambling Cyanobacteria Community Dynamics Related to Environmental Factors. Frontiers in Microbiology. 7.
Status: Published
Bentzon-tilia, M., Farnelid, H., Jürgens, K., Riemann, L. (2014). Cultivation and isolation of N2-fixing bacteria from suboxic waters in the Baltic Sea. FEMS Microbiology Ecology. 88 (2). 358-371.
Status: Published
Farnelid, H., Harder, J., Bentzon-tilia, M., Riemann, L. (2014). Isolation of heterotrophic diazotrophic bacteria from estuarine surface waters. Environmental Microbiology. 16 (10). 3072-3082.
Status: Published
Farnelid, H., Bentzon-tilia, M., Andersson, A.F., Bertilsson, S., Jost, G., et al. (2013). Active nitrogen-fixing heterotrophic bacteria at and below the chemocline of the central Baltic Sea. The ISME Journal. 7 (7). 1413-1423.
Status: Published
Alonso-saéz, L., Waller, A.S., Mende, D.R., Bakker, K., Farnelid, H., et al. (2012). Role for urea in nitrification by polar marine Archaea. Proceedings of the National Academy of Sciences of the United States of America. 109 (44). 17989-17994.
Status: Published
Farnelid, H., Andersson, A.F., Bertilsson, S., Al-soud, W.A., Hansen, L.H., et al. (2011). Nitrogenase gene amplicons from global marine surface waters are dominated by genes of non-cyanobacteria. PLOS ONE. 6 (4). e19223.
Status: Published
Riemann, L., Farnelid, H., Steward, G.F. (2010). Nitrogenase genes in non-cyanobacterial plankton : prevalence, diversity and regulation in marine waters. Aquatic Microbial Ecology. 61. 225-237.
Status: Published
Farnelid, H., Tarangkoon, W., Hansen, G., Hansen, P.J., Riemann, L. (2010). Putative N-2-fixing heterotrophic bacteria associated with dinoflagellate-Cyanobacteria consortia in the low-nitrogen Indian Ocean. Aquatic Microbial Ecology. 61 (2). 105-117.
Status: Published
Farnelid, H., Öberg, T., Riemann, L. (2009). Identity and dynamics of putative N-2-fixing picoplankton in the Baltic Sea proper suggest complex patterns of regulation. Environmental Microbiology Reports. 1. 145-154.
Status: Published

Article, review/survey (Refereed)

Farnelid, H., Turk-kubo, K., Del carmen munoz-marin, M., Zehr, J.P. (2016). New insights into the ecology of the globally significant uncultured nitrogen-fixing symbiont UCYN-A. Aquatic Microbial Ecology. 77 (3). 125-138.
Status: Published

Chapter in book (Other academic)

Farnelid, H., Riemann, L. (2008). Heterotrophic N2-fixing bacteria: overlooked in the marine nitrogen cycle?. Nitrogen Fixation Research Progress. New York, Nova Science Publishers. 409-423.

Doctoral thesis, comprehensive summary (Other academic)

Farnelid, H. (2013). Distribution and activity of nitrogen-fixing bacteria in marine and estuarine waters. Doctoral Thesis. Växjö, Kalmar, Linnaeus University Press.

Manuscript (preprint) (Other academic)

Mollica, T., Farnelid, H., Lindehoff, E., Lundin, D., Pinhassi, J., et al. Phosphorus acquisition strategies among phytoplankton and free-living bacterial communities in the Baltic Proper.
Amnebrink, D., Pontiller, B., González, J., Lundin, D., Andersson, A., et al. Seasonal dynamics and life cycle strategies of the cyanobacterium Aphanizomenon in the Baltic proper.
Lindehoff, E., Mattsson, L., Olofsson, M., Svensson, F., Farnelid, H., et al. Performance and biomass stability of 5-year outdoor microalgal cultivation for CO₂ removal from cement flue gas.
Sörenson, E., Farnelid, H., Lindehoff, E., Legrand, C. Resource partitioning between phytoplankton and bacteria in the coastal Baltic Sea.
Mattsson, L., Sörenson, E., Capo, E., Farnelid, H., Hirwa, M., et al. Functional diversity facilitates resilience to environmental changes in long-term microalgal cultivation system.
Mattsson, L., Farnelid, H., Hirwa, M., Olofsson, M., Svensson, F., et al. Seasonal nitrogen removal in an outdoor polyculture at Nordic conditions.
Amnebrink, D., Pontiller, B., Bunse, C., Lundin, D., Farnelid, H., et al. Genome-resolved analysis reveals transcriptional transitions across seasons in Baltic Sea prokaryotes.
Mollica, T., Lindehoff, E., Lundin, D., Pinhassi, J., Olofsson, M., et al. Seasonal phosphorus acquisition among pelagic microbial communities across the Gulf of Bothnia, Baltic Sea.

Artistic output (Other (popular science, discussion, etc.))

Rödén, I., Farnelid, H., Hägglund, H. (2025). Arktis – Berättelser från isens kant.
The exhibition consisted of ten watercolour paintings by the artist Ida Rödén and a film featuring an interview with researcher Hanna Farnelid and a film featuring an interview with the artis Ida Rödén. It also included workwear and various objects that illustrated life aboard the icebreaker. There was also a printed booklet with the watercolors.
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